The object of this invention is a conduit collar and a method for installing a conduit collar into a hole made into a concrete or stone structure.
In industrial construction work it is at times necessary to insert pipes, hoses, conductors, etc., through structures. The normal procedure is to use a diamond drill to bore a hole in the desired spot for passing through the pipes, etc. As the items to be passed through must not come into contact with the surrounding structure, it is necessary to provide the hole with a protective collar to prevent the entry of water and falling material. As the conduit collar it may be used a pipe with a flange welded thereto for its fastening and sealing. Often it is also necessary to have the concrete structure around the hole pick dressed to accommodate the flange prior to the final mounting of the collar. Using wedge anchors, the collar pipe is then fastened by its flange to the concrete structure. This is followed by concrete being cast over the flange to provide well sealed fastening. The resulting surface may require finishing.
Another way of installing a conduit in a concrete structure is to weld starter bars onto the conduit collar sheath. The collar is then inserted in the hole. The gap between the collar pipe and the hole periphery is then boarded up from below and concrete is poured into the gap to fuse the collar with the concrete structure. The formwork boards are dismantled once the concrete has set.
Yet another way to execute a conduit is to use two pipes, one inside the other and both tapering in the same direction. Here too, the external pipe has to be provided with a flange for the pipe to stay in the hole. Sealing compound is also often needed between the pipe sheaths. Another precaution is to bolt the flange of the other pipe to the floor.
The disadvantages of the above methods include time consuming installation, the labour input of several persons, and several work stages (pick dressing, casting of concrete, welding and formwork). The fastening of the boarding underneath the hole is difficult because high elevations or cramped spaces necessitate different scaffolding for the assembling and dismantling of the formwork. The latter method necessitates the use of two pipes.